As I drive around the area, I can see that some of the winter wheat planted last fall has responded well to the above average precipitation received over the winter months.
Winter wheat production can be improved and input costs reduced with good knowledge of growth and development. Seeding date, irrigation scheduling, fertilizer, and pest control are more effective if accurately timed to crop development.
One of the first steps to take this spring is to take an assessment of winter damage can be done before or after spring green up. If it is before spring green up, remove small cores of plants from representative areas of the field and place plants at room temperature with lights.
If air temperatures are below the lethal point during sampling, place plants in an insulated cooler to prevent cold temperature damage that could indicate more damage than exists in the field. Healthy plants should be examined for both new root and leaf development, as leaf development alone is not a good indicator of survival.
After spring green up, surviving plant stands can be assessed by the following method:
To determine the number of plants per square foot:
1. Use a yardstick or cut a dowel rod to a 3-foot length.
2. Place the measuring stick next to an average-looking row and count all plants in the 3-foot length of the row.
3. Record the number.
4. Repeat the counting process in at least five other locations well-spaced around the field. Record all numbers.
5. Average all the stand counts from the field.
6. Last, calculate plants per square foot with the following equation:
a. (average plant count × 4)/row width in inches
Replanting with a spring crop should be made by comparing yield potential of the surviving plant stand with expected yield potential of the spring crop.
In-season fertility management is also important to maximize production. Nitrogen (N) is the plant nutrient most often limiting wheat yields. If no soil test information is available, the total amount of N required to produce a given potential yield is based on a requirement of 2.7 lbs. N per bushel of winter wheat. The total fertilizer needed to produce a crop includes: residual inorganic N (from soil test), mineralizable N, and fertilizer N.
The best time to top-dress fertilizer is at Feekes 5, to ensure nitrogen is available to the plant by the jointing stage or Feekes 6. Feekes 5 is when the meaningful tillers have developed and the growing point is moving above the soil surface.
It is important for producers to decide how they are going to allocate water to their wheat crop and consider the critical periods for crop water use. Moving into spring, the main goals is to maximize the number of seeds per head so it is critical to hit the jointing stage with water. If water is available, it is also very beneficial to irrigate at flowering.
Once spring green-up occurs, water use gradually increases until late May or early June. As winter wheat reaches the boot stage of growth, water use is near its peak. At this stage, the plant begins to turn the energy it receives into grain production. Even though grain is being produced, water use begins to drop off at nearly the same rate as it increased. Approximately four weeks after peak water use, the winter wheat nears maturity.
Use caution if irrigating during the early spring to reduce the risk of bring the plant out of dormancy prematurely or applying water when the soil profile is full. Irrigation in the spring should only be used to avoid plant water stress and plant desiccation.
Disease management in winter wheat hinges primarily on prevention. Unlike many weed and insect problems, diseases and the yield losses they impose are difficult to control once infection and disease development have occurred. Chemical controls, often sought after disease symptoms and crop damage are apparent, are frequently not available or economical once wheat diseases become established.
Wheat fields should be scouted for winter annual weeds. If present, these weeds should be treated by mid-April, before weeds bolt. When properly established, irrigated winter wheat is very competitive with summer annual weeds. If broadleaf weeds emerge, there are several herbicides that provide excellent control with minimal wheat injury. Growers should select herbicides with minimal soil residual activity in order to maintain maximum crop rotation flexibility.
Feekes Scale, The Feekes scale of wheat development is a common tool used to describe the growth stage of a wheat crop.